Old technology version of a mag base drill for producing relatively large holes on site. Basic method of use is to make a small pilot hole to locate the drill point then arrange some sort of screw jack or equivalent to put feed pressure on the pointed centre at the top. Then ratchet away whilst adjusting the screw to keep pressure on. Surprisingly fast in anything but the most obdurate materials as a sharp drill will take a very thick chip.
Often its possible to find a solid point in the main structure to support the pressure screw. If this isn't possible there is normally there is some sort of upright in the kit which can be fixed to the work surface by clamps or drilled holes with a cantilever arm carrying the pressure screw.
Yours is a pretty modern example being arranged to take morse taper drills rather than square drive end variety used with earlier types. Looks as if it has the pressure screw built into the device too. Which is often more convenient than having it on the arm or jack.
The Cole drill and other similar devices are a lighter duty version working on similar principles.
If you anticipate putting holes over a 1/2" or so into metal structures too big to get under the shop drill it may be worth having about the place.
Clive.
PS. Bob, thats a superb link you found about these devices. Well done.
Edited By Clive Foster on 25/04/2015 11:14:50
Edited By Clive Foster on 25/04/2015 11:15:44